Preparation techniques of fiber composites commonly involve initially infiltrating a woven fabric of structural fibers, such as glass or carbon, with a reactive monomer solution. Then, the infiltrated fabric is placed in an oven, hot press, or autoclave to raise the temperature of the part to fully cure the product and maximize its mechanical properties.
One significant disadvantage of this process is the lengthy fabrication. For thick composite parts, curing can require greater than 8 hrs. Furthermore, the energy required to heat the composite during that time is considerable, increasing the overall cost of fabrication. Large ovens and autoclaves are required, which further increases cost.
Continuous curing uses a propagating curing reaction to reduce fabrication time and minimize the occurrence of thermal spiking during cure. (Journal of Reinforced Plastics and Composites 1993, 12 (5), 520-535.) However, in earlier examples of continuous curing, epoxy laminates had to be applied one at a time as they were frontally cured perpendicular to the fabric to prevent the reaction from being quenched. The curing process also limited the parts to either flat or cylindrical geometries to allow for laminates to be applied one layer at a time. Furthermore, the front was slow to propagate at less than 1 cm/min.
Accordingly, there is a need for a cost effective and rapid method of curing layered woven fabrics into composites of any desired geometry or shape.